package com.gome.axwl.aoc.web.util;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class ZipUtil {


    /**
     * 将多个文件压缩
     * @param fileList 待压缩的文件列表
     * @param zipFileName 压缩文件名
     * @return 返回压缩好的文件
     * @throws IOException
     */
    public static File getZipFile(List<File> fileList, String zipFileName) {
        File zipFile = new File("/tmp", zipFileName);
        try {
            // 文件输出流
            FileOutputStream outputStream = new FileOutputStream(zipFile);
            // 压缩流
            ZipOutputStream zipOutputStream = new ZipOutputStream(outputStream);

            int size = fileList.size();
            // 压缩列表中的文件
            for (int i = 0; i < size; i++) {
                File file = fileList.get(i);
                zipFile(file, zipOutputStream);
            }
            // 关闭压缩流、文件流
            zipOutputStream.close();
            outputStream.close();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return zipFile;
    }

    /**
     * 将文件数据写入文件压缩流
     * @param file 带压缩文件
     * @param zipOutputStream 压缩文件流
     * @throws IOException
     */
    private static void zipFile(File file, ZipOutputStream zipOutputStream) throws IOException {
        if (!file.exists()) {
            return;
        }
        if (!file.isFile()) {
            return;
        }
        FileInputStream fis = new FileInputStream(file);
        BufferedInputStream bis = new BufferedInputStream(fis);
        ZipEntry entry = new ZipEntry(file.getName());
        zipOutputStream.putNextEntry(entry);

        final int MAX_BYTE = 10 * 1024 * 1024; // 最大流为10MB
        long streamTotal = 0; // 接收流的容量
        int streamNum = 0; // 需要分开的流数目
        int leaveByte = 0; // 文件剩下的字符数
        byte[] buffer; // byte数据接受文件的数据

        streamTotal = bis.available(); // 获取流的最大字符数
        streamNum = (int) Math.floor(streamTotal / MAX_BYTE);
        leaveByte = (int) (streamTotal % MAX_BYTE);

        if (streamNum > 0) {
            for (int i = 0; i < streamNum; i++) {
                buffer = new byte[MAX_BYTE];
                bis.read(buffer, 0, MAX_BYTE);
                zipOutputStream.write(buffer, 0, MAX_BYTE);
            }
        }

        // 写入剩下的流数据
        buffer = new byte[leaveByte];
        bis.read(buffer, 0, leaveByte); // 读入流
        zipOutputStream.write(buffer, 0, leaveByte); // 写入流
        zipOutputStream.closeEntry(); // 关闭当前的zip entry

        // 关闭输入流
        bis.close();
        fis.close();
    }
}
